Document Detail


Morphological and electrophysiological study on the inferior nodal extension and transitional cellular band in the rabbit atrioventricular junctional area.
MedLine Citation:
PMID:  15109444     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Advances in catheter ablation procedures for the treatment of supraventricular arrhythmias have created the need to understand better the morphological and electrophysiological characteristics of the inferior nodal extension (INE) and transitional cellular band (TCB) in the atrioventricular (AV) junctional area. METHODS: Firstly, we observed the histological features of 10 rabbit AV junctional areas by serial sections under light microscopy. Then we recorded the action potentials (APs) of transitional cells (TCs) in the INE, TCBs, AV node, and ordinary right atrial myocytes from the AV junctional area of 30 rabbits using standard intracellular microeletrode techniques. RESULTS: Under light microscopy, the INE appeared to be mostly composed of transitional cells linking upward to the AV node. Four smaller TCBs originated in the orifice of the coronary sinus, the region between the septal leaflet of the tricuspid valve and the coronary sinus, the inferior wall of the left atrium, and the superior interatrial septum, respectively, all linking to the INE or the AV node. Compared with ordinary atrial myocytes, the AP of the TCs in both the INE and the TCBs had a spontaneous phase 4 depolarization (not present in ordinary atrial myocytes), with a less negative maximum diastolic potential, a smaller amplitude, a slower maximum velocity of AP upstroke, and a longer action potential duration at 50% repolarization (APD50) and at 30% repolarization (APD30). The AP characteristics of these TCs were similar to those of the AV node, except that the velocities of the phase 4 spontaneous depolarization were slower and their action potential durations at 90% repolarization (APD90) were shorter. Moreover, APD50 and APD30 of the TCs of the TCBs were shorter than in the case of TCs of the AV node. CONCLUSIONS: The TCs of the INE and TCBs are similar to slow response automatic cells. They provide a substrate for slow pathway conduction. In addition, repolarization heterogeneity exists in the AV junctional area.
Authors:
Song-Mei Xie; Xiao-Lin Niu; Er-Dan Dong; Ke-Xin Du; Feng-Dong Ling
Related Documents :
15541264 - Comparative roles of the atrial septal aneurysm versus patent foramen ovale in systemic...
12116804 - Mustard procedure in atrial situs inversus: three-dimensional ablation of intra-atrial ...
15851154 - The safety and efficacy of multiple consecutive cryo lesions in canine pulmonary veins-...
25065624 - Effect of hirulog-like peptide on middle cerebral artery occlusion-induced brain injury...
18412084 - Novel catheter positioning technique for atretic pulmonary valve perforation.
19902134 - Tetralogy of fallot with persistent fifth aortic arch: echocardiographic diagnosis.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Chinese medical journal     Volume:  117     ISSN:  0366-6999     ISO Abbreviation:  Chin. Med. J.     Publication Date:  2004 Apr 
Date Detail:
Created Date:  2004-04-27     Completed Date:  2004-07-08     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7513795     Medline TA:  Chin Med J (Engl)     Country:  China    
Other Details:
Languages:  eng     Pagination:  532-7     Citation Subset:  IM    
Affiliation:
Department of Cardiology, Second Hospital, College of Medicine, Xi'an Jiaotong University, Xi'an 710004, China.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Action Potentials
Animals
Atrioventricular Node / cytology*,  physiology
Female
Male
Rabbits

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Electrical heterogeneity of canine right ventricular transient outward potassium currents.
Next Document:  Experimental study on the mechanism of sex difference in the risk of torsade de pointes.